use crate::ffi::CString; use crate::path::SMALL_PATH_BUFFER_SIZE; use crate::{imp, io, path}; use alloc::vec::Vec; #[cfg(not(target_os = "fuchsia"))] use imp::fd::AsFd; /// `chdir(path)`—Change the current working directory. /// /// # References /// - [POSIX] /// - [Linux] /// /// [POSIX]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/chdir.html /// [Linux]: https://man7.org/linux/man-pages/man2/chdir.2.html #[inline] pub fn chdir(path: P) -> io::Result<()> { path.into_with_c_str(imp::process::syscalls::chdir) } /// `fchdir(fd)`—Change the current working directory. /// /// # References /// - [POSIX] /// - [Linux] /// /// [POSIX]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/fchdir.html /// [Linux]: https://man7.org/linux/man-pages/man2/fchdir.2.html #[cfg(not(target_os = "fuchsia"))] #[inline] pub fn fchdir(fd: Fd) -> io::Result<()> { imp::process::syscalls::fchdir(fd.as_fd()) } /// `getcwd()`—Return the current working directory. /// /// If `reuse` is non-empty, reuse its buffer to store the result if possible. /// /// # References /// - [POSIX] /// - [Linux] /// /// [POSIX]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/getcwd.html /// [Linux]: https://man7.org/linux/man-pages/man3/getcwd.3.html #[cfg(not(target_os = "wasi"))] #[inline] pub fn getcwd>>(reuse: B) -> io::Result { _getcwd(reuse.into()) } fn _getcwd(mut buffer: Vec) -> io::Result { // This code would benefit from having a better way to read into // uninitialized memory, but that requires `unsafe`. buffer.clear(); buffer.reserve(SMALL_PATH_BUFFER_SIZE); buffer.resize(buffer.capacity(), 0_u8); loop { match imp::process::syscalls::getcwd(&mut buffer) { Err(io::Errno::RANGE) => { buffer.reserve(1); // use `Vec` reallocation strategy to grow capacity exponentially buffer.resize(buffer.capacity(), 0_u8); } Ok(_) => { let len = buffer.iter().position(|x| *x == b'\0').unwrap(); buffer.resize(len, 0_u8); return Ok(CString::new(buffer).unwrap()); } Err(errno) => return Err(errno), } } }